GRAND FORKS, N.D. (AP) -- Authorities are beefing up security for this weekend's college hockey series in Grand Forks between rivals North Dakota and Minnesota.

During a Sioux-Gopher game in October 2009, two fights broke out in Ralph Engelstad Arena on the UND campus. In one of them, a man suffered a fractured skull. No charges were filed in the case.

UND Police Lt. Tracy Meidinger says during the games Friday night and Saturday night, campus police will have five officers in the arena, three more than usual.

Arena spokesman Chris Semrau says arena security usually numbers about 20 officers, but for the weekend series the number will be boosted by about half a dozen.

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